Axial flow compressor



March 20, 1945.

A. P EJPLANIOL AXIAL FLOW COMPRESSOI Filed Oct. 16, 1941 2 Shets-Sheet 1 INVENTOR ANDRE, PAUL EUGENE PLAN/0L ATTORN EYS March 20, 1945. A. P. E. PLANIOL 2,371,705

I AXIAL FLOW COMPRESSOR Filed Oct; 16, 194i 2 Sheets-Sheet 2 IN\(ENTOR A/vae pAL/l. fags/v5 PLAN/01 Patented Mar. 20, 1945 AXIAL FIDW COMPRESSOR Andre Paul Eugene Planiol, Huntington, N. Y.

Application October 18, 1941, Serial No. 415,190 In France February 10, 1941 3 Claims.

The present invention relates to machines such as blowers, compressors or the like wherein power is utilized to increase the pressure a fluid. The invention is particularly concerned with the helical or helico-eentrifuga yp of such machine, that is, one wherein the fluid flow is purely helical or helico-centriiugal, and comprises an improved machine which has a high eiiiciency and whichincludes means for regulating the generated pressure differential while maintaining constant the rotational speed. In accordance with the invention, the new machine may deliver either a variable or a constant weight of fluid per unit of time as desired.

The new machine is characterized by the provision of grids of vanes which are orientable around axes disposed normally to the rotational axis of the machine and in the radial direction therefrom in combination with helicoid fans of the classic type, thenumber of ians. and the number of vanes and their particular shape depending upon the particular use to which the machine is to be put. There may be the samenumber of grids of radial orientablevanes as there are helicoid fans constituting the rotatable blades of the machine, or the number of grids may be more or less than the number of fans, according to the amount of power to be transmitted to the iluid and the pressure difierential to be created.

The principle of the invention may be applied to a wide variety of helical or helico-centrifugal machines. As a particular example, the invention will be described as embodied in compressors suitable ior supercharging aircraft engines.

For a better understanding of the invention reference may be had to the accompanying drawings, of which I Fig. 1 is a sectional view through an axial flow compressor constructed according to the invention;

Figs. 2 and 3 are vector diagrams explanatory oi the theory of the invention; and

Fig. 4 is a sectional view through a helico-centrifugal flow compressor illustrating another embodiment of the invention.

In Fig. 1 is shown a compressor having three helicoidfans I, 2 and 8. The particular number of fans is immaterial as a greater or fewernumber could be employed. In this particular embodiment of the invention the fans are mounted on a shaft 5 and secured thereon by a nut l;- the shalt being mounted in bearings 8. In accordance with the invention a pluralityof grids of orientable vanes 1, 8, 8 are carried by shafts I, I and I which are rotatably mounted in the casing III of the compressor. The number of these grids of vanes can be varied, depending upon the desired difference between the minimum and maximum pressureto be created. Any suitable means may be provided for orienting the vanes about their axes. As an example, in Fig. 1 the ends of the shafts I, 8 and 8' beyond the casing III are shown as secured to levers II, If and I3 respectively, the levers carrying pins I 4, I5 and I6 which pass through apertures in rings I1, I8 and I8 respectively. Thus, rotational movement of ring I! about the axis of the compressor effects rotation of vanes I by turning levers I I, and similarly rotation of rings IB and I9 rotate vanes 8 and 9 respectively. The rings I'I, I8 and I9 may be rotated separately or together, as desired; suitable linkage being provided to connect the rings together for their appropriate movement and according to the relationship to be established between the angular displacement of the vanes I, t and 9 around their respective axes or oscillation. For example, if it is desiried to obtain equal angular movements of the three vanes, the rings Il, It and I 9 could be made of a single piece, movement of which would give an equal rotation to the levers II, I2 and I3. If, on the contrary, it is desired to have unequal angular displacement of the vanes, rigid linkage could still be provided between the rings, the levers being made with unequal lengths and different orientation, or,

as shown, a bar 23' having longitudinal slots for reception of the pins I4, l5 and It could be pivotally mounted on the casing III for simultaneous unequal rotation of the vanes upon pivotal movement of the bar by a handle 28. The rings could of course be'kept independent of each other and any suitable means provided for establishing an appropriate mutual relationship between the grids of vanes. Instead of the particular mounting of the vanes illustrated, suitable gears, racks, cams or the like could be employed.

In operation of the machine of Fig. 1, the gas to be compressed reaches the compressor from the'collector 20 and passes at first through the grid comprising the orientable vanes I. The passage through the vanes communicates a kinetic momentum to the gas depending upon the orienthe fan 2 and thereafter through the vanes 9 and the tan 3 is similarly operated upon by the respective vanes and fans.

Eulers relation connecting the power W fur nished by the fan to the fluid, the flow of weight oi the gas per unit of time being I, may be written-- consequently, as the inlet radii are same and the angular velocity is constant. the tangential speed at each considered radius will be constant, henceand thereiore-,

W-FICWI o) I! we consider the phenomenon occurring at the first couple formed by the orientable vanes 1 and fan I" when traversed by a fluid, and it we assume that the angular velocity and the flow of mass per unit of time I, are kept constant as indicated hereabove, then according to the orinetation given by the levers II to the blades constituting the vanes I, the absolute speed of the fluid leaving the vanes and entering the first fan I will be more or less inclined with respect to the plane normal to the rotating axis of the compressor; it may be directed in the direction of rotationor in the opposite sense. For simplicity, let us neglect the case when the absolute speed A is directed in an opposite sense to the rotation 01' the machine but both theoretically and practically this case can not be excluded and may be used in certain special conditions. We thus suppose A is directed so that its projection do on the tangential speed co! the tan is in the same sense as c as shown in the vector diagrams Figs. 2 and 3. In Fig. 2 the projection oi the vector As on the vector c is indicated as an. R0 represents the relative speed Thus variation of orientation of the vanes 1 simultaneously varies in the same direction the power transmitted to the fluid and the theoretical elevation of pressure. This is true within extended limits, depending only on the aerodynamical properties of the grids of vanes formed by the vanes I and fan I which are chosen according to the properties to be achieved. The succeeding couples comprising the grid of vanes 8 and fan 2 and the grid of vanes 8 and fan 3 function in an analogous manner to that above described in connection with vanes I and fan I and generate respectively pressures of H: and H3. The total theoretical increase in pressure H, created by the machine is thus- H =H1+H2+H a same way as the total power W=W1+Wa+Wa and varies in the tion, design a machinehaving any number of fans and orientable vanes. .Instead of all of the vanes being orientable some could be fixed according to the known techniques of the axial polycellular compressors it the diflerence between the minimum and maximum pressure generated does not require all the grids oi vanes to take part in the regulation of the pressure. In this way the machine may be simplified but at the cost 01' a lowering oi the efliciency of the machine for when fixed vanes are substituted for orientable vanes it is necessary to increase the change in the inclination of the other vanes to obtain the same variation in the total generated pressure diiterential. v

- I1 it is desired to permits variation in the mass of fluid passing through the machine per unit of of the fluid at the inlet of the fan. A1, projected as m on the tangential speed c, and R1 are the absolute and relative speeds of the fluid at the outlet of the fan. We see that the diilerence F 01-00 01' the projection on c at the inlet and outlet oi' the tan is equal to mn. The power transmitted to the fluid is thus proportional to the product of mu and the speed 0. II we change the orientation of thevanes I, for example it we turn them nearer to the normal of the plane of the speed 0 so that we increase the angle of the new absolute speed A'o with c, we obtain the diagram 01 Fig. 3 where the component of A'o normal to c,-

which represents the axial speed of the fluid, keeps the same value as in Fig. 2 in accordance .with the assumption that the mass of fluid per unit of time is constant. The new projection a'o is much less than the value an, thus nm' is much greater than nm and the power transmitted to the fluid which is proportional to 0X mn", will time and also permit variation in the pressure while the rotational speed is constant, the present invention permits this to be achieved by disposing at the outlet of the last fan a supplemental grid of orientable vanes the influence of which on the mass of fluid being the more important as the number of vanes is decreased.

In Fig. 4the invention is illustrated as embodied in a helico-centriiugal compressor having two axial tans Ia and 2a and a centrifugal impeller 3a discharging through difiuser vanes 2| into the scroll 22. Instead of the inlet scroll 20 of the embodiment of Fig. 1, I have shown an axially arranged air intake 20a which is a more eflicient form for the intake 01' large air flows.

The vanes la, 8a and 8a are mounted like vanes be greatly increased as will also be the generated I pressure.

I! we denote by Hi the theoretical increase of pressure of the fluid, we have I. H =W=- XcXmn or '1, 8 and 9 of Fig. 1 for oscillation about their respective axes, exceptthat levers Ila coupling ring lia with vanes Ila are shown as relatively shorter than levers Ila and Ila, whereby for equal rotation of the rings Ha, I Baand Ila, as by the bar 23 secured to the ring Ito, and having slots 25 for reception of the pins Ila and I60, vanes will be given greater angular rotation than vanes Ia and 8a. The arrangement of Fig. 4 of axial fans Ia and 2a with the radial impeller is gives increased pressure ratio for a given speed and the multiple sets oi orientable vanes in between the different tans permit large variations in the generated pressures and may permit, in some cases, a reduction in the number of fans employed. The machine of Fig. 4 constitutes a compressor of the helico-centriiugal type with an adjustable pressure regulated by a set of vanes situated solely in the axial part of the machine.

The present invention applies to any type of machine of compression, displacement or elevation of fluid such as ventilators, blowers, com-- pressors, pumps, etc.

I claim:

1. A machine for increasing the pressure of a fluid, comprising in combination a casing, a shaft rotatable therein, a plurality of helicoid fans mounted on said shaft, grids oi vanes carried by the casing and each positioned upstream of one of said fans, and means accessible from without said casing for simultaneously oscillating the vanes of each of said grids through unequal angles about axes radially disposed with respect to the axis of the shaft.

2. A compressor or the like comprising in combination a casing, a plurality of helicoid fans and a helico-centriiugal i'an mounted for rotation in the casing about a common axis with the helicocentriiugal fan comprising the last stage of the compressor, grids of vanes cooperating with said fans in the-passage oi fluid through the compressor, each grid being positioned upstream of one of said fans, and means accessible from without said casing ior oscillating the vanes of each oi.

said grids about axes radially disposed with respect to the common axis of rotation of the fans.

3. The combination according to claim 2 wherein said last mentioned means are operable to simultaneously oscillate the vanes of the grids upstream of the helicoid fans through equal angles and the vanesof the grid upstream of the hence-centrifugal grid through relatively greater angles.

ANDRE PAUL EUGENE PLAN'IOL.

CERTIFICATE OF CORRECTION.

Patent No. 2,571,706.

March 2O 191MB ANDRE PAUL EUGENE PLANIOL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, first column, line 11;, before "same" insert -the-- "radii" insert -and outlet--; same line before line 28. for "orinetation" read --orientation-;

and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 5th day of June, A. D'. 1915.

I (Seal) Leslie Frazer Acting Commissioner of Patents.

The present invention applies to any type of machine of compression, displacement or elevation of fluid such as ventilators, blowers, com-- pressors, pumps, etc.

I claim:

1. A machine for increasing the pressure of a fluid, comprising in combination a casing, a shaft rotatable therein, a plurality of helicoid fans mounted on said shaft, grids oi vanes carried by the casing and each positioned upstream of one of said fans, and means accessible from without said casing for simultaneously oscillating the vanes of each of said grids through unequal angles about axes radially disposed with respect to the axis of the shaft.

2. A compressor or the like comprising in combination a casing, a plurality of helicoid fans and a helico-centriiugal i'an mounted for rotation in the casing about a common axis with the helicocentriiugal fan comprising the last stage of the compressor, grids of vanes cooperating with said fans in the-passage oi fluid through the compressor, each grid being positioned upstream of one of said fans, and means accessible from without said casing ior oscillating the vanes of each oi.

said grids about axes radially disposed with respect to the common axis of rotation of the fans.

3. The combination according to claim 2 wherein said last mentioned means are operable to simultaneously oscillate the vanes of the grids upstream of the helicoid fans through equal angles and the vanesof the grid upstream of the hence-centrifugal grid through relatively greater angles.

ANDRE PAUL EUGENE PLAN'IOL.

CERTIFICATE OF CORRECTION.

Patent No. 2,571,706.

March 2O 191MB ANDRE PAUL EUGENE PLANIOL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, first column, line 11;, before "same" insert -the-- "radii" insert -and outlet--; same line before line 28. for "orinetation" read --orientation-;

and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 5th day of June, A. D'. 1915.

I (Seal) Leslie Frazer Acting Commissioner of Patents. 

